As technology development and demand for a mobile device have increased, demand for a secondary battery as an energy source has rapidly increased. Conventionally, a nickel-cadmium battery or a hydrogen ion battery has been used as the secondary battery. However, a lithium secondary battery is recently widely used because charging and discharging is free due to rare memory effect in comparison with a nickel-based secondary battery, a self-discharge rate is very low, and an energy density is high.
The lithium secondary battery mainly uses a lithium oxide and a carbonaceous material as a positive electrode active material and a negative electrode active material, respectively. The lithium secondary battery includes an electrode assembly in which a positive electrode plate and a negative electrode plate, respectively coated with the positive electrode active material and the negative electrode active material, are arranged with a separator therebetween, and an outer member, that is a battery case, which seals and receives the electrode assembly together with an electrolyte solution.
The lithium secondary battery includes a positive electrode, a negative electrode, and a separator and an electrolyte interposed therebetween. Depending on which material is used for the positive electrode active material and the negative electrode active material, the lithium secondary battery is classified into a lithium ion battery (LIB) and a polymer lithium ion battery (PLIB). Generally, an electrode of the lithium secondary battery is prepared by applying the positive or negative electrode active material to a current collector made of aluminum or copper sheet, mesh, film, foil, or the like and then drying the same.
Generally, a secondary battery has a module structure in which unit battery cells are stacked, and a plurality of battery modules may be stacked to configure a battery pack. The battery pack may be used as an energy storage device and is configured to prevent the danger caused by external physical factors and satisfy installation environment and installation conditions. The battery pack may be used for a variety of purposes such as home or industrial applications.
Here, various kinds of installation members such as a battery circuit breaker may be installed at a case of the secondary battery. However, if the case coupled by bolts or the like is entirely separated for operating the installation member, the maintenance is not easy since a lot of working time is needed.